“So far the nuclear deal has been transactional rather than transformational,” says Gary Samore, who served for four years as President Obama’s coordinator for arms control and weapons of mass destruction. Both the US and Iran have “major incentives” to keep the deal in force and to avoid its unraveling, he says. But that doesn’t mean it will lead to a transformation – either in bilateral relations, or in Iranian behavior. “For Obama, [the deal] allows the US to focus on defeating the Islamic State on the battlefield” rather than worrying about a progressing Iranian nuclear program, says Dr. Samore, who spoke in New York this week at a United Against Nuclear Iran conference. A deal collapse would “blow up” a “tacit US-Iran agreement” around the coming battle to retake Mosul from the Islamic State, he says... The longer-term prospects of both the nuclear deal and US-Iran relations are less certain, Samore says. “I don’t have much confidence the deal is going to remain in force for 15 years,” he says.